ALEXANDER VON HTJMBOLDT. 175 circumstances, the latent forces which caused inequa- lities and elevations, and formed the solid part of the earth, change the mathematical into a physical form, of surface. On the first form; science has made all its graduated measurements of the earth. By eleven such measurements, of which nine were made in this cen- tury, while the two others date from the old Peruvian times, and the East Indian astronomy, it has ascer- tained the incurvations of this surface and the size of the earth, and it has been found by this means that the flattening of the earth spheroid, in which the denseness of the mass must increase towards the centre., - is nearly equal to the ^^th part. These measure- ments for ascertaining the incurvations of the earth^s surface have not only been made by graduated measure- ments, and by observations of the pendulum oscilla- tions and the divergence in the moon's course, by geometrical astronomic means, "but also from conclu- sions on the observed movements, on the powers generated, and by these powers back on their origin. By these measurements, of which eight were made in Europe, it has been ascertained that the semi- diameter from the centre of the earth to the poles is 3.1. geographical miles shorter than the semi-diameter from the centre to the equator ; this shows that the surface of the earth from the poles to the equator is swelled by a little more than 4*4- times the height of Mont Blanc. The observations made by the oscilla- tions of the pendulum have become of extreme im- portance for science, and Humboldt justly says: " When Galileo, as a boy, saw during church service that by the duration of the oscillations of the cande- labra the entire height of a church dome might be measured, he could not suppose that the pendulum, rod would one day be carried'from pole to pole to determine the form of the earth, or rather t<> produce the conviction that the unequal density of the earth strata affects the second pendulum by intricate local influences which reveal themselves similarly on large surfaces/'